There are about two million patients suffering from acute hepatitis and chronic hepatitis in Japan, and the development of medicines to remedy these diseases is constantly underway. It is known that a dibenzocyclooctadiene type lignan contained in the fruit of Schisandra chinesis BAILL belonging to the genus Schisandraceae is valuable as a remedy for these liver diseases (see Japanese Patent Application No. 60-122560), and the development of a chemical having a higher liver ailment-moderating action is now desired.